1. Field of the Invention
The present invention relates to a control system for an automatic transmission, and more particularly, to a control system for integratedly controlling an engine and an automatic transmission.
2. Background Art
Since an electrically operated throttle valve is mechanically disconnected with an accelerator pedal, the relationship between the depression amount of the accelerator pedal and a throttle opening angle can be arbitrarily chosen. Therefore, the electrically operated throttle valve has the advantage of being able to choose a feel of operation of the accelerator pedal as a driver desires. The inventor of the present invention currently studies an integrated control system of an engine and automatic transmission using this electrically operated throttle valve.
It is an object of the present invention to provide an integrated control system for an engine and an automatic transmission capable of performing a shift control of the automatic transmission by properly estimating a driving force required by a driver.
The control system comprises a first detecting means for detecting an accelerator pedal opening angle, a second detecting means for detecting a vehicle speed, a third detecting means for detecting a speed of the engine, a first calculating means for calculating a required horsepower value based on the accelerator pedal opening angle and the vehicle speed, a second calculating means for calculating a required intake air amount per stroke based on the required horsepower value and the engine speed such that the engine outputs the required horsepower value, an engine control means for establishing a fuel injection amount of a fuel injector and a throttle opening angle of a throttle valve based on the required stroke intake air amount per stroke and a judging means for judging a gear shift of the automatic transmission based on the required horsepower value and the vehicle speed by reference to a shift judgment criteria. The shift judgment criteria comprises a plurality of full throttle horsepower curves obtained per each gear position when the accelerator pedal opening angle is maximum in relation to the vehicle speed and a plurality of zones corresponding to respective gear positions and enclosed by two neighboring full throttle horsepower curves.